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What is the Function of the Extruder in the 3D Printer? – A Comprehensive Guide

what is the function of the extruder in the 3D printer

3D printing is indeed very fun and interesting but questions such as what is the function of the extruder in the 3D printer may seem to be a little scary. Actually, things are not that scary. While you read ahead you shall know about it from the depth you shall not only know about it in detail but surely shall have much better control while operating your 3D printer

What is the function of the extruder in a 3D printer

what is the function of the extruder in the 3D printer

Before we go ahead and focus on the functions of the 3D printer extruder, it is important for us to learn first about what an extruder is. The 3D extruders are a part of the 3D printers that dispense materials either in the semi-liquid or liquid form. It does so in order to deposit it into multiple forming layers within the volume of 3D printing. In certain cases with the help of the 3D printer filament extruder, it meets the purpose of depositing a bonding agent that comes into great use for solidifying the material of the extrusion that actually is in a powder form. So, this is what is the function of the extruder in the 3D printer.

Types of the 3D printer extruder and its functions

Extruders are indeed very important parts of a 3D printer. So, if you wish to learn about what is the function of the extruder in the 3D printer, you need to know about the types of extruders are there in the 3D printer and this shall give you knowledge of their job roles or functions as you may call them. 

In case of the professional 3D printers, you shall find that there are two types of extruders. They are Direct and Bowden. But sometimes in some 3D printers, you shall even have a third type of extruder as well. It is called dual extrusion.

Direct Extruder

In this extruder, the filaments begin from the cog and go all the way to the hot end and the cold end in a single piece. It means that the gear and drive that helps the filament to move are directly above and attached to the hot end.  The extruder becomes slower as a result of sitting directly on the hot end. Yet, there are many people who prefer to use the direct extruder for printing flexible 3D filaments. The filaments have less distance to cover with these direct extruders and get easily molten and deposited. This also arises lesser issues as well.

Bowden Extruder

what is the function of the extruder in the 3D printer

Here, the hot end and the cold end get separated by the PTFE tube that the filament moves along. Here the cold end does not sits directly over the hot end because it gets separated by the tube. Contrary to the Direct extruder, the Bowden extruder is very fast and light. The reason for this is that the part that moves is only its hot end. The cold end remains affixed on a single point of the printer.

These extruders are known for printing models of higher quality and provide continuous designs as well. you cannot use flexible materials with this Bowden extruder. If you do not keep any space for the filament to wiggle or move, it shall perfectly move along the tube to the hot end.

Dual Extruders

There are some printers that have two or more extruders. It allows you to print many materials at a single time. And also two models at the same time too. Having this extruder, you shall be able to accelerate the process of your printing as you are having the support of two moving tools that are melting the filament and depositing it at the same time as well. It also features the IDEX which is an independent dual extrusion system.

Usually, the Dual extruders move along together and at the same time as well but in the case of the IDEX, it operates freely and individually. This results in making possibilities for increasing productivity, and efficiency, and saves time as well. 

How an extruder works

An extruder basically works through the cold end and the hot end. 

Cold end

It consists of the stepper motor, a few toothed gearing, hobbed gear or bolt, an idler with a loaded spring for holding the filament, and PTFE tubing for guiding the filament. In this cold end, the stepper motor is responsible for driving the motion that has the extrusion of the filament of the 3D printers. And then the brushless DC motor takes up the responsibility of reaching a greater level of precision.  It moves a shorter distance at a time but gives a powerful torque yet at a low speed.

Hot end

To this end, the filament is passed for melting and extrusion. Here, the filament passes through a hot chamber where it changes its state from solid to liquid. And then the filament feed tube gets the filaments directly in the heat breakage using the heat sink. Thus, during the process of printing the filaments moves from the cold end toward the hot end. From there it further gets processed into the heat break meeting the nozzle. This 3D printer nozzle happens to be a small piece having a hole through which it expels the molten filament.

Usually, you shall find this nozzle to have been screwed at the hot end of the heater block. You can even be able to interchange these nozzles. Although the nozzles come in different sizes, the most regular one for practice is the one that is 0.4 mm. 

So, as you have already known by now although 3D printers work through the extruders, yet, there are some 3D printers too that do not require the support of the extruders. Instead, they perform on different printing technology. Details such as this differentiate one model of the 3D printer from the other falling under the same brand name. And this is why different models of 3D printers have a different price to them as well.